Alone
Acknowledgement: the data for this Tidy Tuesday comes from Dan Oehm (https://github.com/doehm/alone)
How has viewership changed over the seasons
## `geom_smooth()` using formula 'y ~ x'Number of viewers per episode of Survivor
Between seasons 1 and 6, viewership of Survivor generally trended
downwards. Following an all-time low in viewership in season 6 (s6 ep 9
is the only episode in the series’ history to have fewer than 1 million
US viewers!), the show has experienced a rebound to levels not seen
since season 5 but it’s a long way to go before it scales the heights of
the season 1 finale.
(The plot above is interactive!)
Average viewership per episode over the first 8 seasons of Survivor in the US
Viewership over the first 8 seasons of Survivor in the US
Why did viewership fall over the first 6 seasons
Perhaps the quality of the show declined?
No! The IMDB rating for Survivor over the first 6 seasons were more or less the same. In fact, the most highly rated season was season 6, despite it having such a low viewership. (This is assuming the IMDB rating is a reliable measure of quality!)
Average IMDB ratings for episodes in the first 6 seasons of Survivor
Perhaps the show became less exciting/dangerous?
Assuming the number of survivalists is a measure of how exciting a season was, viewership may have declined because the show became less exciting to watch as contestants found themselves in less perilous situations.
It does not seem to be the case that more survivalists being medically evacuated is correlated with a higher viewership. This makes sense as the IMDB ratings across seasons are very similar.If anything, there seems to be a possibility that having fewer survivalists being medically evacuated is correlated with a higher viewership.
Number and percentage of medically evacuated survivalists and average viewership over 6 seasons of Survivor
Number and percentage of survivalists NOT medically evacuated and average viewership over 6 seasons of Survivor
Running Pearson’s correlation test indicates that the positive
correlation between viewership and surivivalists not being medically
evacuated is significant.
##
## Pearson's product-moment correlation
##
## data: notEvacuatedBySeason$mean_viewership and notEvacuatedBySeason$`Number of survivalists not medically evacuated`
## t = 2.4286, df = 6, p-value = 0.05126
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
## -0.001189892 0.941586313
## sample estimates:
## cor
## 0.7040734##
## Pearson's product-moment correlation
##
## data: notEvacuatedBySeason$mean_viewership and notEvacuatedBySeason$`Percentage not evacuated`
## t = 3.8115, df = 6, p-value = 0.008848
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
## 0.3354273 0.9705668
## sample estimates:
## cor
## 0.8412556Could it be that viewers prefer the show when the health of participants is in less danger?
Predicting how many viewers season 10 might get
Number of viewers per episode of Survivor
Autocorrelation of viewership
However, as demonstrated by the partial autocorrelation, there is likely noise associated with correlations from previous episodes driving up the autocorrelation coefficient at each lag. Before fitting a model, the data needs to be transformed so that the mean and variance are stationary.
Partial autocorrelation of viewership
Following transformation, we can apply an ARIMA model to the data and
predict how many viewers the next season of Survivor will obtain!
| Episode | Predicted number of viewers in the US (millions) |
|---|---|
| 1 | 1.437960 |
| 2 | 1.522137 |
| 3 | 1.474678 |
| 4 | 1.483932 |
| 5 | 1.527913 |
| 6 | 1.492780 |
| 7 | 1.493292 |
| 8 | 1.487127 |
| 9 | 1.479134 |
| 10 | 1.558419 |
| 11 | 1.513843 |